What to watch for in Tuesday's presidential debate

President Donald Trump and Democratic nominee Joe Biden will have an opportunity to contrast their visions for the country in a televised debate. Likely topics include Mr. Trump’s tax history, the Supreme Court, and the coronavirus response.

First Look

President Donald Trump and former Vice President Joe Biden will square off on Tuesday in their first presidential debate. With five weeks to go until the Nov. 3 general election, the stakes are high.

The televised debate, to be hosted in Cleveland, will likely cover a range of topics, from Mr. Trump’s tax history to the government’s coronavirus response, as well as the political fight surrounding the Supreme Court. Both Mr. Trump and Mr. Biden will likely use the debate stage to rally their base as well as to appeal to undecided voters.

The face-to-face match-up comes after The New York Times revealed that Mr. Trump, a wealthy former businessman and reality television star, paid only $750 in federal income taxes in both 2016 and 2017, and no federal income taxes in 10 of the previous 15 years through 2017.

The report, which Mr. Trump called “total fake news,” gives Mr. Biden a fresh opening to make his case that his working-class roots better position him to understand the economic struggles of everyday Americans than the billionaire occupying the White House.

Mr. Trump has also faced persistent questions, based on his statements about a rigged election, about whether he will accept the voting results should he lose. With millions at home watching, how will he respond if Mr. Biden pushes him to commit to a peaceful transfer of power?

Both candidates will scuffle over Mr. Trump’s nomination of Amy Barrett to the Supreme Court. Mr. Trump has been using his pick to rally his conservative voter base and distract from his record on the coronavirus and other matters, while Mr. Biden has been warning of a conservative Supreme Court’s potential threats to health care and abortion rights.

Biden’s moment?

For Mr. Biden, the debate will serve as sort of a reintroduction. While he has held limited events in some states and given media interviews, the coronavirus pandemic has largely rendered him off-stage for months.

That has allowed Mr. Biden to keep the focus where he wants it: on Mr. Trump and his performance in office. But on Tuesday, the Democratic nominee will have to make his own case for the presidency, while giving concise answers and avoiding some of the verbal mishaps that have beset him throughout his political career.

With Mr. Biden leading in polls, a strong outing could place Mr. Trump in even worse shape. A weak one could reshape the race.

Coronavirus, protests, the economy

Faced with alarming coronavirus statistics or unrest in the streets, Mr. Trump has been quick to blame Democratic officials, activists, scientists – anybody but him. One of Biden’s goals will be making sure the public understands that Mr. Trump is the one in charge.

Trump could use his office to his advantage, as he often tries to do with the economy. Voters like to see a president take responsibility – for the good and the bad.

John Geer, an expert on voter opinion at Vanderbilt University, wonders if Mr. Trump will react poorly to sharp or unfriendly queries from moderator Chris Wallace of Fox News. “Will Trump have a tough time answering non-softball questions?” Mr. Geer said.

Potential for misinformation

As Mr. Trump’s campaign rallies show, he can fire off falsehoods in machine-gun fashion. Examples include the Republican’s common claim that the U.S. economy was operating at historic levels before the pandemic (it wasn’t) and that the virus has largely dissipated (it hasn’t).

Attempting to constantly pin Mr. Trump to the truth could turn Mr. Biden into a real-time fact-checker – possibly to the Democrat’s detriment.

“It’s a big mistake to try and do that,” said Aaron Kall, the director of debate at the University of Michigan. “You have to focus on your own agenda.”

Mudslinging

Mr. Biden has worried aloud about reacting to Trump’s propensity for ad hominem attacks. On the campaign trail, the former vice president has sometimes shown flashes of temper, getting his “Irish up” as he calls it.

Mr. Trump in a tweet on Sunday went as far as to suggest Mr. Biden will be on performance-enhancing drugs during the debate, signaling that perhaps there is little he will not do or say to rattle Mr. Biden and disrupt the proceedings.

Polls show that Mr. Trump’s frequent questioning of Mr. Biden’s mental fitness has registered with some voters. Mr. Trump’s team will be looking for moments where Biden seems flustered or unsure to exploit as a viral video.

“If the president lies, call it a lie. If he attacks Biden personally, just shrug it off and not get personal,” Mr. Geer said. “Biden needs to continue to be presidential and tough, even if there is some mud on his suit jacket.”

This story was reported by Reuters.